1. Field of the Invention
The present invention relates to a bourdon tube pressure gauge.
2. Description of the Related Art
As a pressure gauge for measuring an internal pressure in a pressure container and the like, there is conventionally known a bourdon tube pressure gauge employing a bourdon tube (refer to Japanese Patent Publication No. 2008-196893A, for example). A bourdon tube pressure gauge described in the Japanese Patent Publication (JP2008-196893A) includes a bourdon tube and a joint to which a rear end of the bourdon tube is fixed. In this bourdon tube pressure gauge, the bourdon tube and the joint are made of metallic materials such as a copper metal and steel. In addition, in the bourdon tube pressure gauge, in order to fix a rear end of the bourdon tube to the joint, the rear end of the bourdon tube is inserted into and brazed to a fitting hole which is formed in the joint
In recent years, needs for reduction in cost of the bourdon tube pressure gauge are increasing in the market. If a resin is used as a material of the joint in response to this, cost of the bourdon tube pressure gauge can be reduced. However, it is impossible to fix by brazing a bourdon tube made of metal to a joint made of a resin, and hence there is a fear of degrading a fixation strength of the bourdon tube with respect to the joint. Accordingly, there is a fear in that generation of pressure inside the bourdon tube results in detachment of the rear end of the bourdon tube from the fitting hole of the joint.